The invention relates to a self-propelled rail-bound transport car with a frontally arranged, elastic bumper and with switch contact means actuated by the bumper upon frontal impact of the bumper against an obstacle for influencing the individual drive device of the transport car, whereby the elastic bumper exhibits a handle contour and is arranged on a rotatably seated lever which is provided with actuation means for the switch contact means.
On the one hand, thus, the bumper is designed in such manner that it forms not only a frontal impact surface but rather also a grasping surface for an operator and, on the other hand, is rotatably seated in such manner that, both upon a frontal loading of the bumper as well as upon a loading in a vertical direction caused by an operator, it actuates the contact device and, thus, prevents a premature initiation of a drive effect on the transport car; the drive can only begin when the transport car is placed on the rail line at that moment at which the operator releases the bumpers designed as handles.
Since the bumper also serves as a handle, the height of the bumper over the rail line carrying the transport car must be selected in such manner that an operator can reach under the bumper without difficulty. Beyond that, a certain minimum height over the rail is also forced in that the bumper must be able to strike against the corresponding bumpers of other transport cars in front of it in curves which lead the rail line from the horizontal into the vertical. This minimum height of the bumper above the profile rail line leads to the result that flat obstacles which lie on the rail are not engaged by the bumper. Such obstacles, however, can represent a danger for the operational security of the entire transport system since, for example, the wheels of the transport car can thereby be lifted, and the transport car can become jammed in the rail line. Insofar as the drive of such a jammed transport car continues, such a disruption can be connected with the destruction of the drive motor. This danger, however, could be countered by means of motor protection switches sensitive to temperature or excess current known per se. The provision of motor protection switches, however, does not meet all demands of accident regulations which are aimed, particularly at avoiding personal injury.